This invention relates to a mounting arrangement for a camshaft and associated valve control elements of an internal combustion engine with a number of spaced bearing sockets and bearing covers for supporting a cam shaft extending along the length of the cylinder head of the engine.
DE 32 20 724 A1 discloses an internal combustion engine with overhead cam shaft for operating the intake and exhaust valves during the combustion of the fuel/air mixture in the cylinders of the engine. The cam shaft extends lengthwise on the cylinder head and is rotatably supported by several cam shaft bearings which are arranged in spaced support intervals and include each a bearing socket and a bearing cover mounted thereon. The cam shaft operates rocker arms which control valves which open and close the intake and exhaust passages in the cylinder head. The rocker arms are rotatably supported by rocker arm support shafts which are supported in bores extending parallel to the axis of the camshaft. In this arrangement however, the rocker arm shafts may experience undesirable bending vibrations which prevent an accurate control of the valves, because the rocker arm shafts have some elasticity and there is some bearing play and the rockerarms transfer such effects to the valves. Under unfavorable conditions, such continuous stresses may even lead to breakage of the rocker arm shaft and, consequently, total failure of the arrangement. Furthermore, it is disadvantageous that the bearing sockets are integrally manufactured with the cylinder head which, for forming the rocker shaft bearing, must be machined in a relatively expensive way. For repairing such camshaft bearings, the whole cylinder head has to be replaced.
It is the object of the present invention to provide a simple arrangement for supporting a cam shaft and the rocker arms for operating the intake and exhaust valves of an internal combustion engine which arrangement requires little mounting space, yet provides for high stability of the rocker arm shaft.